Correlation between body mass index and disease activity in patients with systemic lupus erythematosus from China

To assess the association between clinical indicators (primarily Body Mass Index, BMI) and disease activity in systemic lupus erythematosus (SLE) populations in a large population-based cohort.

Consecutive patients with SLE were enrolled to investigate the relationships among clinical features, inflammatory and biochemical indicators, and disease activity parameters. Significance values were adjusted by Bonferroni correction for multiple tests, then differences between continuous variables were analyzed by Kruskal Wallis tests. Associations were assessed using multiple linear regression to adjust for potential confounders, including glucocorticoid use, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and lipid levels.

A total of 400 SLE patients (375 women and 25 men) were included. Among them, 61 patients (15.25%) were classified into the low BMI group (BMI < 18.5 kg/m²), 267 patients (66.75%) into the normal BMI group (18.5 kg/m² ≤ BMI < 25 kg/m²), and 72 patients (18.00%) into the high BMI group (BMI ≥ 25 kg/m²). BMI was negatively correlated with SLE disease activity index (SLEDAI) score (ρ = -0.11, P = 0.02). This inverse association remained significant in multivariate linear regression after adjusting for potential confounders, including glucocorticoid use, CRP, ESR, and lipid levels. Patients in the low BMI group exhibited higher mean SLEDAI scores and a greater proportion of moderate to severe disease activity (SLEDAI ≥ 10) compared with the normal and high BMI groups. Additionally, anti-dsDNA, complement component 3, white blood cell count, alanine aminotransferase, neutrophil count, and hemoglobin were significantly different between the low BMI group and the other two groups.

These findings indicate an association between low BMI and higher SLE disease activity. However, further investigation, particularly through prospective studies, is needed to determine whether low BMI exerts a detrimental effect on disease activity.

Not applicable.